Daan Mertens, Jacob C. Douma, Bram B. J. Kamps, Yunsheng Zhu, Sophie A. Zwartsenberg, Erik H. Poelman
This is a plain language summary of a Functional Ecology research article which can be found here.
During their lifetime, plants face the difficult challenge of growing and reproducing while under attack by a multitude of herbivorous insects. Herbivores directly affect a plant’s reproduction by consuming flowers or seeds, but can also affect plant reproduction through two different indirect mechanisms. First, they can affect how a plant grows and reproduces by, for example, diminishing the resources available to the plant or its photosynthetic capacity (a plant-mediated effect on reproduction). Second, damage by herbivores can affect the attractiveness of the plant to later-arriving herbivores. This changes the community of insects building up on the plant over time, and ultimately how substantial the pressure on plant reproduction will be (a community-mediated effect on reproduction). Even though herbivory is one of the most observed and studied interactions in terrestrial ecosystems, the interplay between direct effects, plant-mediated effects and community-mediated effects makes it difficult to estimate how substantial the impact of herbivory on plant reproduction will be.
We tested if controlled herbivory early in a plant’s life could affect its development, the herbivore community with which it interacts, and ultimately, it’s reproduction. Hereto, we inoculated plants of four different wild plant species early in their development with either caterpillars, aphids, or left plants untreated. By modelling the plant- and community-mediated effects in our study system, we predicted that any effects on reproduction by our herbivore treatment were most likely going to be caused by changes in plant development rather than by changes in the herbivore community. Interestingly, we found that plants were able to attenuate the impact of the herbivore treatment on their development, negating any clear effects on plant reproduction. While we could not identify the mechanism by which the plants compensated for damage early in their development, inoculated plants seemed to have shifted their growing strategies in such a way that they levelled the playing field and managed to reproduce as successfully as the untreated plants. Our study suggests that herbivory early in the life of plants has the potential to affect plant reproduction predominately through changes in plant development. However, these effects are limited, and plants are often able to attenuate and compensate the effects.
Functional Ecology: Plain Language Summaries 